package daydayup;

import java.util.Arrays;

public class Q1576 {

    public static void main(String[] args) {

    }

    public String modifyString(String s) {
        char[] array = s.toCharArray();
        int n = array.length;
        for (int i = 0; i < n; i++) {
            char front = '*';
            char back = '*';
            if (array[i] == '?') {
                if (i > 0) front = array[i - 1];
                if (i < n - 1 && array[i + 1] != '?') back = array[i + 1];
                for (char j = 'a'; j < 'd'; j++) {
                    if (j != front && j != back) array[i] = j;
                }
            }
        }
        return String.valueOf(array);
    }
}
